Validation of the simplified criteria for diagnosis of autoimmune hepatitis in Chinese patients.

BACKGROUND & AIMS: In 1999, the International Autoimmune Hepatitis Group (IAIHG) revised the diagnostic criteria for autoimmune hepatitis (AIH). It subsequently developed the simplified criteria in 2008 to enhance clinical applicability and practicability. In this study, we validated the simplified diagnostic criteria in Chinese patients with AIH or other chronic liver diseases in comparison with the revised original criteria.
METHODS: Diagnostic scores were determined using the revised original criteria and the simplified criteria in 405 patients with diverse liver diseases. The sample included 127 patients with AIH type I diagnosed by the descriptive criteria, 77 patients with primary biliary cirrhosis (PBC), 6 patients with AIH-PBC overlap syndrome, 47 patients with drug-induced liver injury (DILI), 36 patients with non-alcoholic steatohepatitis (NASH), 82 patients with chronic hepatitis B (CHB), and 30 patients with chronic hepatitis C (CHC). The simplified criteria were compared to the revised original criteria based on sensitivity, specificity, and predictability for the pre-treatment diagnosis of AIH.
RESULTS: The simplified criteria had sensitivity and specificity of 90% and 95%, respectively, for the diagnosis of probable AIH in the Chinese patients. This compares well with the more rigorous revised original criteria, which had sensitivity and specificity of 100% and 93%, respectively, for probable AIH. On definite AIH, the simplified criteria had sensitivity and specificity of 62% and 99%, respectively, compared to 64% and 100% for definite AIH by the revised original criteria. In addition, the predictabilities of the revised original criteria and simplified criteria were 96% and 94% for probable AIH, and 88% and 87% for definite AIH, respectively, in our groups. Using the revised original criteria, 84 patients were diagnosed with definite AIH. On the other hand, among these 84 patients, the simplified criteria diagnosed only 61 patients with definite AIH (accordant diagnosis) and provided the 23 other patients with downgraded diagnosis. Comparison of the clinical and laboratory features of these two groups (accordant diagnosis vs. downgraded/excluded diagnosis) showed that the patients with downgraded diagnosis had significantly higher histological scores than the patients with accordant diagnosis.
CONCLUSIONS: The simplified criteria are comparable to the revised original criteria and have high sensitivity and specificity for the diagnosis of AIH in Chinese patients. Liver histology is critical for the diagnosis of AIH especially when using the simplified criteria. Further study or prospective evaluation is needed to confirm these observations, however, due to the small group of CHC patients as well as the absence of primary sclerosing cholangitis (PSC) patients in our study.